The English colony of Maryland was founded by Lord Baltimore[?] who on March 25, 1634 led the first settlers into this area which would soon become one of the few dominantly Catholic regions among the English colonies in America. The Maryland toleration act was one of the first laws that explicitly tolerated varieties of religion (as long as it was Christian), and is sometimes seen as a precursor to the First Amendment.

Originally, based on an incorrect map, the royal charter granted Maryland the Potomac River and territory northward to the fortieth parallel. This was found to be a problem, because this would put Philadelphia, the major city in Pennsylvania, within Maryland. The Calvert family, which controlled Maryland, and the Penn family, which controlled Pennsylvania, engaged two surveyors, Charles Mason and Jeremiah Dixon, to survey what became known as the Mason-Dixon line which would form the boundary between their two colonies.

The state bird is the Baltimore oriole[?]; the state flower is the black-eyed susan[?]; state sport is jousting; state dog is the Chesapeake Bay Retriever; state cat is the calico cat; and the state song is "Maryland, My Maryland." Nickname is "The Old Line State."